Importing from Mendeley

You can import your library of references from other
bibliographic management tools, like Mendeley.
To do this, you first need to export your library from Mendeley
into a format Papers can import.

Exporting from Mendeley

Select all your entries in Mendeley

Navigate to File -> Export

Give your file a name. You can select what file type to save
your library as, in this case we will use "BibTeX" under "save as
type"

Click on Save

Importing to Papers

Once you have exported your entire library from Mendeley in XML
format, you can import it to Papers.

Start Papers, and navigate to File -> Import ->
BibTeX

Select your library file you exported earlier from
Mendeley

Click 'import'

Your library entries will now be imported to Papers.
Unfortunately, importing collections or folder information is not
supported. As you are exporting it is important to select all your
library entries. When only one entry is selected you might be only
exporting that one entry, or you may be prompted whether you want
to export the selection or the entire library.